Method of producing water gas



Filed July l5 C. W. ANDREWS ET AL METHOD OF PRODUCING WATER GAS Feb. 5,1929.

Patented Feb. s, 1929.

vUNITED STATES PATENT OFFICE.

CHARLES W. ANDREWS, 0F DULUTH, MINNESOTA, AND HERMAN A. BBASSEBT, OFCHICAGO, ILLINOIS.`

METHOD 0F PRODUCING WATER GAS.

Application led July 15, 1922. Serial-No. 575,254.

This' invention 4relates to' a new and iinproved method of producinwater gas.

Our method has for its o ject the carbonizing of a relatively deep bedof coal bypassing gases through the fuel bed, which consists of severalsuperimposed layers of coal on top of hot coke, the purpose being topreheat the upper layers with the gases passing through from the lowerla ers and of colnpressing thev lower layers v the weight of the upperlayers in order to increase the speed and efiiciency of thecarbonizingprocess and producing more solid coke for use' in making timecompresses the lower layers of coal,-

thereby making a more solid coke, more suitable for subsequent gasmaking. The process is carried out by charging an ordinary water gasgenerator with coke and by alternately air blasting and steaming,bringing the fuel charge up to the gas making temperature. Theheat-carriedout of the generators by the blast gas is stored in suitableair or steam re enerators, or both. When the coke has reaced a properdepth and these regenerators have reached a proper temperature, theactual process of carbonization begins.

At this point the first layer of coal is dropped on top of the hot cokein the generator. The. preheated steam from the regenerators is thenintroduced into the`bot tom of the enerator andv sent upward through theot coke, producing highly heated blue water gas which continues upwardthrough the layer of raw coal just charged.

This operation results in the rapid heating of the coal and theimmediate volatilization of some of its volatile matter and is continuedlong enough suiciently to fuse the coal to render it suitable for thesuccessive air blasting period, that is, to prevent the carrying out ofsmall particles of solid fuel with the blast gases. Means are providedfor agitating the fuel and this agitation 'is particular] important whenusing fuels which tent to mass and fuse together. The poking oragitation keeps the mass broken up and insures the passage of the hotgases uniformly.throughout the fuel. It minimizes channeling and theformation of uncoked masses and aids materially in preventingclinkering.

` At the end of this period the makingof water gas isv resumed andcontinued until the coke has regained its proper temperature. when aYsecond layer of coal is added. 'flhe operation is contlnued' exactly asbeore.

.The highly heated gases passin upward continue the carbonization of therst layer of coal and start the carbonization of the next layer ofcoal.y The operation may be continued in this manner untila sufficientthickness of the coal bed has been reached to give the best results, inregard to utilization and distribution of the hot gases throu h the coalbed, as well as in regard to t e compressing of the lower layers of coalby the superimposed weight for thel purpose of producing a more solidcoke.

After a sufcient thickness of coal is added,` theamount of water gasmade is such as to keep the level of the coke at the proper height foreflicient operationf In other words, new layers of coal are added atregular intervals to keep the generators full so that a continuousoperation results and the maximum eiciency is derived.

This process may be carried out either in a sin le generator where thecarbonizing of the uel is accomplishedboth by hot blue water gas and airb ast gases passing throu h the fuel or can be app ied 1n the case o acyclic operation in which bv the use of several sets blue water gas onlyis passed through the fuel as a carbonizing medium.

We have illustrated an apparatus adapted for carrying out our process inthe accompanying drawings, in which- Figure 1 is a somewhat diagrammaticplan view partly in section, showing a water gas generator and theaccompanying stoves, and` Figure 2 is a vertical section takenapproximately on line 2-2 of Figure 1.

The water gas generator unit A is of the usual type, comprising theshell 5 and refractory' lining b.` It is provided with the fuel chargingopening 7 and the grate 8. The usual doors 9 are rovided for removal ofclinkers, as is also t e usual ash cleanout door 10. The passage 11 isprovided for the withdrawal of the gas as made, this passage beincontrolled by valve 12.

e t of the water 'gas generator A is connecte by assage 13 with the topot the steam heater 1i the passage beine controlled by valve 11i. Thepassavo 15 leads from the passe 13 adjacent the heater B and is con- .tat 16 to the unit A. at a point belovv the te, The passage l5 iscontrolled by valve 17. y y

The heater B is connected with air stoves C and D by passages 18 and 19,respectively, these passa es being controlled by valves 20 and 2l. T estoves C and D are provided with eaust passages 22 and 23, respectively.These stoves are also provided with intake assages 24 und 25,respectively, for the intro uction of air, these passages beingcontrolled b valves 26 and 2?. 'lhe stove C'is connected by passage 28to the unit A. at a point below the grate, this passage 28 beingcontrolled by valve 29. The stove D is similarly connected to the t A bypassageo controlled b valve bl. The steam heater B is provide with theintake assage 32 controlled by valve 33. The o er or stirring rod 34 isshown iis-inserte through the top covering the opening 'Z und the po ermay b e rotated and reci rocated by any suitable means (not shown Suchdevices are old in the art in connection vvvith i producers.

, In the operation of the installation, the unitA. is partially ed withcolic or similar carbonaceous rendue. Air is introduced through passage2d to stove C and passes thence through sw 28, past valve 29, to thelower rtion of the gas making unit. This air ows up through the gratosand passes through the mass of carbonaceous resi due, causingcombustion, which raises the temperature of the residue. The air blast Qd are led out through passa 13, valve 14e ing open, to the steam heaterB. It will be understood that valve 17 is closed, as is valve 33. Thehot blsst gases pass down through the heater B und through assage i9,

ast valve 21, to the air stove D. ir may be introduced to burn the blastgases if desired., The valves 31 and 27ers closed and the blast gasespass out of the stove through discharge passage 23. They may beexhausted to the atmosphere or their remaining heat may be utilized inother stoves or in waste heat boilers, as desired.

When the stove D has been suiciently heat ed, the operation willpreferably be partially reversed to the ext that the incoming air willbe introduced through stove D and through passage 30 to the unit A,vwhile the mousse and 31 both beine shut oil. Valve 14 is closed andvalve is opened A layer of coal or other raw fuel is nov;r placed uponthe heated residue.

Steam is then introduced through passa 32, @past valve 33, and lpassesupward g through the highly heate steam heater in which it is preheated.The preheated steam is led through passages 13 and 15 and is introducedinto the as making unit below the ate. This highlgy heated steam passesup t rough the heated mass of oarbonaceousresidue and water gas isevolved. The heated water gas passes up through the raw fuel on theresidue and carries od volatile contents from the fuel. The gases andvapors are led od through passage 11, past valve 12, to any suitableWashing and scrubbing apparatus, and then to a gas holder or otherapparatus, as may be desired. -It may be passed through a superhter tofur the volatile content or throu h a carburetor for adding enrichingmaterial before being to a superheater Due to the high tem rature towhich the residue has been raise and the high tcmperature of the steam,the water gas reaction takes place rapidly and eliciently. The rcs-lidue is not materially chilled by the introduction of the steam sincethe steam is 'at a temperature approximately that of the residue.

The groesse is continuous and when the heater has had its temperaturereduced in heating the incoming steam, and when the temperature of thecarbonaceous residue has become lower than that suitable for efficientoperation, the rocess is again reversed and the residue is b asted byair heated in either of the stoves C or D, whichever ma have last heatedby the passage o blast '2%' Another la er of coal or raw fuel is nowplaced upon e mass of material in the unit and the process ,continues asbefore The fuel is preferably introduced in relativel thin layers atcomparatively short and may be stirre by the poker during the gas makingprocess.

The unit will becomel filled to the proper working height by the succvelayers of fuel, the lowermost layer being gasmaking coke or theequivalent and theto layer relatively rawjuel. The fuel is gra uallycokcd or reduced to carbonaceous residue suitable for gas maln'n as itworks its way down the unit. It w lbe understood that the ash iseriodically removed from below the grato.

he weight of the superposed column of material is an important factor inassuring that the coke or carbonaceous residue in the gas making zone isof a suitable texture and quality for gas generation.

While it has been stated that the layers of raw fuel are added after aperiod of air blasting and `before the subsequent gas making period andthis method is considered prefer.- able, it is not essential. When theunit'is fully in operation, the amount of fuel added will correspond tothat reduced toash ingas generation during the corresponding period.:

The operation may be varied in many ways within the scope of theappended claim; for

instance5 it may prove more economical to.

add more heat to the -air and less or more to the steam.

We claim:

The method of. water gas production which comprises, air'blasting amass` of carbonaceous residue to raise its temperature, plac-` ing alayer of coal on said residue, passing steam into said heated residue toform blue water gas, passing the heated blue water gas through the coal,whereby the heat of thel blue water gas serves to yolatilize thevolatile content of the coal, agitating the layer of coal v Signed atChicago, Illinois, this 12th day of July, 1922.

. CHARLES W. ANDREWS. 'HERMAN A. BRASSERT.

